1. Field Of The Invention
The present invention relates generally to an air flow apparatus and, more specifically, to an air flow apparatus which provides a thin and continuous layer of jetting fluid.
2. Description Of The Prior Art
Inglis U.S. Pat. No. 4,046,492, which issued Sept. 6, 1977, discloses an air flow amplifier. This amplifier includes an annular nozzle for producing a column of jetting fluid. A similar prior device known as a curtain transvector provides a thin layer or curtain of jetting fluid. It has a linear nozzle for producing this curtain of fluid.
A curtain transvector includes a body member which defines: an elongate plenum chamber; at least one inlet providing communication between the plenum chamber and a compressed air source; and a linear outlet or nozzle which restricts the pressurized air flowing out of the plenum chamber and produces a thin film of jetting air. The inlet is a round opening whose center lies normal to the longitudinal axis of the plenum chamber.
A great number of curtain transvector applications require a flat, continuous curtain of fluid without any discontinuities. Many prior art transvectors do not meet this requirement. The air curtains they provide includes low pressure zones or "dead spots". This occurs for the following reasons:
Compressed air enters the plenum chambers of these prior devices, flowing in a direction perpendicular to the longitudinal axis of the plenum chamber. The air flow at the inlet is highly turbulent because the air must change direction abruptly to flow into the chamber and because the air expands rapidly when it enters the plenum. This turbulence produces the low pressure zones.
To solve this problem, one prior device includes an inlet at one or both ends of an elongate plenum chamber. In this device, the air flows into the plenum chamber without having to change its direction of flow. This device, however, increases the overall length of the unit whereby a smaller percentage of usable length is available to provide the curtain of air. This increased overall length precludes its application where the device must conform to cramped mounting locations. In addition, standard pipe fittings installed at one or both ends of the plenum chamber, significantly increase the overall length of the device, and, substantially reduce the percentage of usable length available.
The air flow apparatus of the present invention provides a mechanism which includes a baffle member disposed in the plenum chamber to isolate the turbulence and distribute and regulate air flow evenly to the linear nozzle of the apparatus. It provides a construction which minimizes the expense of manufacture and assembly and gives precise uniform and reliable performance. The air flow apparatus of the present invention comprises a small number of components which provide a continuous curtain of jetting fluid.